Smokin' guerrilla letters?

Scandinavias biggest business magazine about media and marketing communication, Resumé, reports that the advertising agency Mecka worked together with Nexans, in order to promote Nexans' new electrical halogen free cables. Having no halogen in the cables apparently makes them "low smoke & flame retardant". (Sorry, the article at Resumé is only in Swedish.)

So, Mecka sent out a first letter that smelled of smoke (written by a fire fighter) and and a second, water damaged, letter (written by a risk engineer). The third letter they sent out was written by Nexans and it adviced the receivers to visit the campaign site. (Unfortunately, Resumé did not link to that site, and I haven't been able to find it...)
EDIT: http://www.nexans.se/halogenfritt/ (Thank you Anders!)

A fun idea, and hopefully a smoke-smelling letter will attract the eyes (or nose) of the recipients.